I've done it - totally manageable if limit to no more than 9-12 credits/term. Must give up anything resembling a social life and if you have a family, they will suffer b/c you will not be available or stressed out for the family-related activities. Entire family burden will shift to your spouse. IMO, not worth it if you have children at home.

I agree. I work full time and have been taking an average of 10-12 credits/semester. It is manageable, but you have to stay focused. If you get into a rhythm and start to relax, you could run into trouble. Explain to friends & family at the outset that they will not see you for the next 4 years except during breaks between semesters. The good thing is it teaches you discipline and excellent organization.